1. Andrew, W.: The alimentary tract of vertebrates. Textbook of Comparative Histology. New York 1959.
2. Bage, G., and R. Olsson: Fine structure of normal, thyroxine-, and goitrogen-treated epithelium 3 cells of the ammocoetes endostyle. Gen. comp. Endocr. 3, 682 (1963).
3. Bargmann, W.: Die Schilddrüse. In: Handbuch der mikroskopischen Anatomie des Menschen, Bd. VI/2, herausgeg. von W. V. Möllendorff. Berlin: Springer 1939.
4. Cowdry, E. V.: Flagellated cells in the dogfish thyroid (Mustelus canis). Anat. Rec. 22, 289–299 (1921).
5. Dempsey, E. W., and R. R. Peterson: Electron microscopic observations on the thyroid glands of normal, hypophysectomized, cold-exposed, and thiouracil-treated rats. Endocrinology 56, 46–58 (1955).